The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent the work is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Wireless communication systems may transmit control packets prior to transmitting data packets in order to prevent interference due to frame collision. For example, frame collision may occur as a result of hidden nodes. The control packets may be request-to-send (RTS) and clear-to-send (CTS) packets. A source node wishing to send a data packet may first transmit the RTS packet to a destination node. The destination node may then transmit the CTS packet back to the source node to initiate data packet transmission. Conventional RTS and CTS packets are designed to prevent transmission interference between two stations.
Many wireless communication systems, however, use multiple antennas and are therefore modeled as multiple-input, multiple-output (MIMO) systems. MIMO systems can increase throughput by transmitting multiple streams over multiple transmit antennas. Examples of MIMO wireless communication systems (hereinafter MIMO systems) include wireless fidelity (WiFi) systems, Worldwide Interoperability for Microwave Access (WiMAX) systems, Long Term Evolution (LTE) systems, and so on. Conventional RTS and CTS packets, however, may not work in MIMO systems.